Chinese hockey referees have a good understanding of rules but they need to improve their foreign language skill which is required at international arena, Olympic-grade umpire Sarah Garnett said Thursday.

After five days of cooperation, four foreign umpires invited to officiate in women's field hockey tournament at the 10th National Games approved the improvement of their Chinese counterparts and gave their advice.

Garnett said,"We can see their great improvement, but they need to gain more experience, and they still have problems in English communication."

The introduction of foreign umpires have boosted fair play and brought in international standard to the national games, Sun Chengmin, an official at Umpire Committee of the field hockey tournament said.

Chinese Field Hockey Association invites four foreign referees this time from International Hockey Federation, all of whom are international-grade umpires from Australia, New Zealand, Malaysia and Germany.

Petra Mueller, an international A-level umpire from Germany, said introduction of foreign referees was good for mutual understanding and the progress of Chinese counterparts.

Sun said,"In fact, Chinese umpires only have a narrow margin to close in respect of ability, and what they lack of is foreign language skills, confidence and authority."

Xiong Ru, an international-grade Chinese umpire, said Chinese Field Hockey Association had been helping them with English training and provided them with more opportunities to officiate at international tournaments.

"We will do our best in self-improvement to gain upgrade, which is also important to the development of field hockey in China," she said.